The present invention relates to a blood measuring apparatus using the electrical resistance method.
There is a blood cell counting apparatus using the electrical resistance method. Such an apparatus includes first and second chambers which communicate with each other through an aperture, in each of which diluted blood for measurement is contained, and in which electrodes are disposed respectively in the two chambers, and performs the blood cell counting (see U.S. Pat. No. 2,656,508).
In the apparatus, proteins in blood adhere to the aperture and the interiors of the first and second chambers. Whereby, the wettability is impaired particularly in the aperture and air bubbles adhere to the aperture. In such a case, the air bubbles are caused to function as a disturbance in measurement by fluid vibration, and therefore it is impossible to obtain an adequate measurement result. When air bubbles once adhere to the vicinity of the aperture, moreover, the air bubbles are hardly removed by a water stream.
Therefore, the aperture and chambers are washed with chlorinated detergent for proteins decomposition which is sucked from the outside of the measuring apparatus. However, the expiration is set in chlorinated detergent because of the property that, when chlorinated detergent comes in contact with the air, the detergent decomposes, and hence management of such detergent is cumbersome. In some countries, import restrictions are imposed on chlorinated detergent. In the case where a measuring apparatus is additionally provided with chlorinated detergent, for example, the importation of the apparatus itself is restricted.
Alternatively, enzymatic detergent may be used in such washing. In the case where enzymatic detergent is used, however, washing must be performed in the state where the liquid temperature is held at a constant temperature, thereby causing a problem in that such washing requires a prolonged period of time.
Also in an apparatus which measures biological fluid other than blood, in the case where adhering materials such as proteins are to be washed away, usually, a similar problem arises.
Furthermore, there is an automatic analyzing apparatus in which a washing solution is produced by electrolysis of a saline solution, and a reaction chamber is washed (see JP-A-11-153604).